Device for vacuum sealing of preserving jars

A device for sealing preserving jars which are provided with a thin metallic essentially disc-like lid, the latter having on its rim a washer of an easily deformable material, the device comprising a hood which is put over the mouth of the jar loosely covered with said lid, and which hood fits tightly on the jar to form an enclosed chamber over said lid, means for connecting a vacuum source to said hood to create a vacuum in said chamber so that the air left within the jar escapes, and an externally manually operated valve means in said hood adapted to press said lid against said jar and then to let the atmospheric air stream into the chamber after evacuation of air has been finished, and only after the lid has been pressed with adequate power, tightly sealing against the top edge of the jar, said valve means being disposed at the center of said hood and comprising a guide tube extending through the hood and terminating in the neighborhood of the lid, a hollow valve cylinder which is closed at its top end slidingly disposed in said tube in sealing engagement and terminating at its lower end in a shoulder to engage the bottom of said tube and function as a stop to limit upward movement of said cylinder, said cylinder being normally biased in its uppermost position, a valve plug slidingly disposed in said cylinder and extending downwardly below said lower end, the outer wall of said plug being spaced from the inner wall of said cylinder to form a valve chamber, said plug being in sealing engagement with said lower end when the plug is in its lowermost position, and allowing communication between said enclosed chamber and said valve chamber when in a raised position, said plug being normally biased in its lowermost position, and inlet bores in said cylinder communicating said valve chamber with the atmosphere, whereby when external manual pressure is initially applied to said top end of said cylinder to provide a downward stroke thereto, first said downwardly extending plug contacts said lid to press the same against said jar, and when continued external manual pressure in an amount to overcome the biasing of said plug is applied to said top end of said cylinder, said stroke continues with concurrent relative movement between said cylinder and said plug thereby causing communication between said enclosed chamber and the atmosphere via said valve chamber and said inlet bores.